1. Field of the Invention
The present invention relates to a system for distributing or providing information through the use of a network.
2. Description of the Prior Art
The information distribution using a network has hitherto been made in such a manner that, like the WWW (World Wide Web) on the internet, a client has transmitted a data name corresponding to information the client desires through the network to an information server being an information provider and has then received the desired information therefrom. FIG. 36 illustrates a typical arrangement of an information distribution system. In the illustration, this prior system comprises an information server 3601 which distributes information, a client 3602 which receives the information therefrom, and a network 3603 which establishes connection between the information server 3601 and the client 3602. The information server 3601 includes a communication control section 3604 for controlling the communication with the network 3603, a data production and acquisition section (which will be referred hereinafter to as a data production section) 3605, and a control section 3606 for controlling the communication control section 3604 and the data production section 3605. On the other hand, the client 3602 includes a communication control section 3607 for controlling the communication with the network 3603, a data holding section 3608 for holding data, a display section 3610 for displaying various kinds of data and messages to the user, an input section 3611 for accepting the input made by the user, and a control section 3609 for taking care of the control of the communication control section 3607, the data holding section 3608, the display section 3610 and the input section 3611.
Referring to FIGS. 36 and 37, a description will be made hereinbelow of the operation of this prior model. First of all, through the use of the input section 3611 of the client 3602, the user gives instructions to the client 3602 so that the client 3602 makes a request for the designated data to the information server 3601. At this time, the control section 3609 of the client 3602 gives instructions to the communication control section 3607 to request the same data therefrom. The communication control section 3607 issues a request for the same data through the network 3603 toward the information server 3601 (step 3701 in FIG. 37). On the other hand, in the information server 3601 side, the communication control section 3604 first accepts the request from the client 3602 side and then makes it known to the control section 3606 which in turn, hands it over to the data production section 3605. The data production section 3605 produces and gets the data corresponding to the data name designated (step 3702). If there is the requested data (step 3703), the operational flow comes in the information distribution operations (step 3704 and the following steps).
The data production section 3605 communicates the produced data to the control section 3606 which in turn, gives instructions to the communication control section 3604 to supply the obtained data to the client 3602 side. In response to the instructions, the communication control section 3604 transmits the same data through the network 3603 to the client 3602 (step 3704). At this time, even if the data requested involves a large amount of data such as image data, all the data are delivered from the information server 3601 through the network 3603 to the client 3602. In the client 3602 side, the communication control section 3607 receives the data from the information server 3601 through the network 3603 and subsequently passes it to the control section 3609 which in turn, once stores it in the data holding section 3608. The same data is thereafter reproduced to be displayed on the display section 3610 (step 3705).
On the other hand, if in the aforesaid step 3702 there is no data to be given, the operational flow shifts to a step 3706 where the data production section 3605 informs the control section 3606 of the fact on no acquisition of the data, while the control section 3606 gives instructions to the communication control section 3604 to give the notice of data supply rejection to the client 3602 side, with the notice being transmitted through the network 3603 thereto. When receiving the data supply rejection notice from the information server 3601 side through the network 3603, in the client 3602 side the communication control section 3607 conveys it to the control section 3609 which in turn, makes the display section 3610 displays the same notice (step 3706).
Furthermore, as another model of the information distribution using the network, there has also been known a communication KARAOKE system employing a laser disk or the like. In this system, for distribution of data, a large amount of data such as image data is placed in a KARAOKE terminal side, while in answer to a request for music data from the terminal the center feeds the music data and an indication code indicating the use of image data to the terminal side. The terminal combines the fed music data with image data reproduced in accordance with the image data use indication code to provide the resultant to the user.
FIG. 38 shows a typical arrangement of this prior system. In the illustration, the system is composed of an information server (center) 3801 which performs the information distribution, a client (KARAOKE terminal) 3802 which accepts the information therefrom, and a network 3803 for making connection between the information server 3801 and the client 3802. The information server 3801 is equipped with a communication control section 3804 for controlling the communication with the network 3803, a data production section 3805 for producing and obtaining the data to be provided, and a control section 3806 for controlling the communication control section 3804 and the data production and acquisition section 3805. On the other hand, the client 3802 is provided with a communication control section 3807 for controlling the communication with the network 3803, a data holding section 3808, a laser disk 3809 being a portable large-capacity data keeping medium, a laser disk control section 3810 for controlling the laser disk 3809, a display section 3811 for displaying various kinds of data and messages to the user, an input section 3812 for accepting instructions from the user, and a control section 3813 for taking charge of the control of the communication control section 3807, the data holding section 3808, the laser disk control section 3810, the display section 3811 and the input section 3812.
Referring to FIGS. 38 and 39, a description will be taken hereinbelow of the operation of this prior system. First of all, through the use of the input section 3812 of the client 3802, the user gives instructions to the client 3802 for request of the designated data from the information server 3801. The control section 3813 of the client 3802 gives instructions to the communication control section 3807 to ask the information server 3801 for the same data. The communication control section 3807 asks the information server 3801 through the network 3803 for the distribution of the same data (step 3901 in FIG. 39). Going the other way, in the information server 3801 side, the communication control section 3804 accepts the aforesaid request the client 3902 makes, and then communicates it to the control section 3806. The control section 3806 passes the name of the data under the request to the data production section 3805. The data production section 3805 produces and gets the data corresponding to the name of the data requested. At this time, since the client 3802 and the information server 3801 render services in a closed system, the client 3802 is equipped with a predetermined laser disk. Accordingly, the data corresponding to the name of the data requested the information server 3801 provides is singly determined, so that the data production section 3805 of the information server 3801 attains the data fixed to the request (step 3902).
The data production section 3805 hands over the obtained data to the control section 3806 which in turn, gives instructions to the communication control section 3804 to send the obtained data to the client 3802. Thus, the communication control section 3804 transmits the same data through the network 3803 to the client 3802 side (step 3903). In the client 3802 side, the communication control section 3807 receives the data from the information server 3801 side through the network 3803 and then hands it over to the control section 3813 which in turn, makes it once stored in the data holding section 3808 and makes it thereafter reproduced to be displayed on the display section 3811. At this time, the control code for displaying image data in the laser disk 3809 the client 3802 retains is included in the data the information server 3801 sends, the control section 3813 controls the laser disk control section 3810 in accordance with the control code so that the image data is derived from the laser disk 3809 and displayed on the display section 3811 (step 3904).
The above-described system has been exemplified by Japanese Unexamined Patent Publication No. 6-102888.
There is a problem which arises with the system having the FIG. 36 arrangement and exhibiting the subsequently mentioned operation, however, in that for distribution of a large amount of data such as a motion picture the data transmission takes a long time due to the restriction in the capacity of the line between the information server and the client, with the result that difficulty is encountered to put the system into practice. For this reason, for the distribution of such motion picture data, the conventional system has been made to shorten the time required for the data transmission in such a way as to restrict the data quantity and the time or deteriorate the image quality to improve the compression efficiency.
In addition, in the system having the FIG. 38 arrangement and exerting the subsequently mentioned operation, the information server side for providing information is made to produce the corresponding data on the assumption of the holding situation of the (image) data in the client side and hence, when the client asks the information server for data which does not conform with the assumption, difficulty is experienced to appropriately reproduce the data the information server provides. Thus, although there is no problem in the case that the system service is rendered in a closed network, the prior system is not suitable for the distribution of information to many and unspecific clients through an open network where a different data retaining situation is taken at every client.